The present invention relates to a screening arrangement for installation in a curb for a skylight in a roof structure.
In order to install a skylight in a roof structure a curb frame is usually fabricated on the site to match an opening cut through the external roof covering and underlying plate members of the roof structure. The curb is composed of four wall members which may be joined together to form a rectangular frame. The curb frame is then positioned on and secured to rim portions of the roof plate members surrounding the opening. Subsequently the curb is usually lined on the internal side of its wall members by suitable panel members, such as plasterboards, forming a shaft extending through the curb as well as the underlying roof structure and insulation.
As the curb in each case is handmade according dimensions of the actual roof structure, the internal dimensions of the curb will be different in each case. Furthermore, in case of a less accurate cutting of the roof opening, frequently parts of the roof plate members may project into the opening at the lower end of the curb, and consequently an individual adaption of the lining members becomes necessary. The need for individual adaption of the lining members forming the internal surface of the curb will frequently reduce the space available for mounting a screening arrangement in the form of a venetian blind, a roller blind or a pleated blind. As a consequence of these conditions the dimensions of standard designs of screening arrangements will usually not fit into the available space.
U.S. Pat. No. 4,762,160 to Bechtold et al. discloses a screening arrangement comprising four rails to be mounted on the internal vertically extending surface of a curb in a roof structure. The rails comprise a top rail carrying a rolled up shade, two side rails guiding the shade when it is unrolled, and a bottom rail. In order to position the rails correctly in the curb, first the appropriate distance from the top edge of the curb must be measured out separately for each rail on the internal surface at the respective wall member of the curb. Subsequently, the rails must one by one be positioned on the internal surface according to the measurement and retained by hand in the position during the fixation of the rail to the curb by means of screws. Obviously, this cumbersome manual mounting procedure is a disadvantage as it is time consuming and consequently costly.
Furthermore, in most cases a standard set of rails will not fit into the curb lining for the reasons discussed above. Consequently, either the screening arrangement must be ordered made to measure or it must be individually adapted on the site to fit the internal surface of the curb formed by the lining. If the screening arrangement is ordered to measure, this results in a considerably higher cost price and an interruption of the installation work, because the screening arrangement cannot be ordered before completion of the individually adapted lining of the curb frame. On the other hand, if the screening arrangement has to be individually adapted on the site, this involves time consuming manual work which is also costly. Furthermore, the rails of the screening arrangement and the axle with the rolled up shade must then be specially designed in order to allow for the manual adaption.
In view of the foregoing, it is an object of the present invention to provide a screening arrangement which permits correct installation in a curb without having to carry out difficult measurements.
It is another object of the invention to provide a screening arrangement which is easier to install than the known arrangements.
A further object is to provide a screening arrangement which will fit into an individually adapted curb without being fabricated to measure or needing cumbersome adaption on the site.
In summary, a screening arrangement for installation in a curb for a skylight in a roof structure is provided. The curb is of the type having four wall members joined together to form a substantially rectangular frame having four corners, and the curb has a top edge and an internal surface facing the inside of the frame. The screening arrangement is of the type comprising four rails being adapted to be mounted on the internal surface of said curb to form a frame in the curb. At least one of the rails is associated with a collapsible screen of which a first end is fixed in relation to said rail and a second end is free. Four corner brackets are provided for mounting at respective corners of the curb, each said bracket having an abutment surface for abutment on the top edge of the curb and a support member for supporting two of said rails.
During installation of the screening arrangement in the curb, first the four corner brackets are placed at respective corners of the curb in such a way that the abutment surface of each bracket abuts on the top edge of the curb. The brackets may then be secured to the curb by means of fasteners, such as screws, nails or the like. Subsequently, each rail is first positioned between two respective corner brackets so that either end of the rail is supported by the supporting member of a corner bracket, and then the rail is secured to the curb by means of fasteners. In this way, no measuring is necessary in order to position the rails correctly in relation to the top edge of the curb, because the corner brackets provide the correct position of the rails in relation to the top edge of the curb. As the rails during their fixation to the internal surface of the curb are supported by the corner brackets, it is not necessary to handhold the rails during fixation and therefore an easier and at the same time more precise positioning is possible. Furthermore, the support member of a corner bracket may be in the form of a plate member adapted to cover the possible gap between the rails at a corner so that this gap is invisible from the inside of the room in which the screening arrangement is installed.
Consequently, a given set of rails each having a standardized length may be utilized for a range of different internal dimensions of a curb, these different dimensions resulting from individual adaption of the curb and its lining. The rails in conjunction with the corner brackets will appear as forming a continuous frame which in the unrolled state of the screen may completely surround the latter in a light-sealed manner. In this way one standard size of screening arrangement will fit different sizes of curb without cumbersome adapting procedures and without any visible adjustments.